Plug in type electric switch



Dec. 27, 1949 F. P. GATES mm m TYPE ELECTRIC swncu 3 Sheets-Sheet 3 Filed April 20. 1945 v L/IVSULA 776W BYH/S ATTORNEYS M l ww Fig. 6

Patented Dec. 27, 1949 PLUGIlN' TYPE ELECTRIC SWITCH Frederic P. Gates, Toronto, Ontario, Canada, as-

signor to The Arrow-Hart & Hegeman Electric 00., Hartford, Conn., a corporation oi Connecticut Application April 20, 1945, Serial No. 589,314

4 Claims. 1

This invention relates to electric switches and more particularly to switches used in connection with electric ranges, or wherever it may be necessary to mount the switch body behind a panel with the operating member in front thereof.

Switches of the sort to which this invention relates often have to be removed from their mounting for repair or replacement. Due to high labor costs and to the prior complicated panel and switch arrangements, it has been troublesome and expensive to remove and repair such switches; and it has ordinarily been beyond the ability of the user to substitute one switch for another.

One object is to provide an electric switch and mounting combination in which the mounting islocated behind the panel and the switch may be readily removed from and replaced in the mounting without removing the panel.

Another object is to provide a switch of the foregoing type in which the switch, as a completely assembled unit, may be plugged into, and removed from, a sub-panel mounting.

Another object is to provide, in a device of the foregoing type, for covering or shielding all the live parts so that when the switch unit is not plugged in, accidental contact by anyone with its live parts will be prevented; and likewise, when the switch is in place, for covering all the live parts of both the switch and its mounting.

Another object of the invention is to provide an improved construction for a device of the foregoing type wherein the parts are compactly arranged, providing a comparatively shallow structure as well as a structure that can be economically manufactured and installed.

Other objects and advantages will become apparent as the invention is described in the accompanying drawings.

In the drawings- Fig. 1 is a section view through mounting, panel and switch units embodying the invention with the mounting and switch unit separated and with the handle removed from the switch unit. The section through the mounting is taken along line I-l of Fig. 4; and the section through the switch unit is taken along line ll of Fig. 6.

Fig. 2 is a bottom view of the switch unit when removed from its mounting.

Fig. 3 is an elevational section view of the switch unit when removed from its mounting in the receptacle base, the section being taken along line 3-4 of Fig. 6.

Fig. 4 is a plan view, partly broken away. of the invention on a panel.

Fig. 5 is an elevational section view of the switch body when removed from its mounting in the receptacle base, the section being taken along line 55 of Fig. 6.

Fig. 6 is a plan view of the switch unit with the switch handle removed.

Referring to the drawings, the invention comprises a combination of a receptacle unit (designated generally by R), a switch unit (designated generally by S) and a panel P behind which receptacle R is mounted. The panel has an aperture ill through which the body of the switch unit may move into the receptacle R.

The panel P may be a part of an electric range and the receptacle may be mounted behind it on separate mounting means or by screws (not shown) passing through the panel into holes, such as l3, according to the range manufacturer's preference.

The receptacle unit comprises a body molded from insulating material with a central cavity I4 for the reception of the body of the switch unit. Preferably the receptacle body, as viewed in plan, is symmetrical about the horizontal center line (see Fig. 4) in which portion of the assembled device has been broken away for the purpose of illustrating, the structure of the interior of the receptacle. Into the bottom surface of the receptacle are molded rectangular recesses such as 22, in which are located receptacle contact members 20. The receptacle contact members are preferably stamped from sheet metal into U-shape with the opposite jaws 20a curved to receive cylindrical plug contact fingers such as 2|, projecting from the bottom of the switch unit as hereinafter described. Cylindrical apertures 24 in the top walls of the recesses 22 permit the entrance of the plug fingers for the purpose of engaging the receptacle contact members. Thus the receptacle contacts 20 are enclosed and shielded and access to them may only be had from the cavity [4 through the apertures 24. This protection is necessary because the receptacle contacts are live parts and the user should be protected against coming accidentally into contact with them. The recesses or pockets 22 for the receptacle contacts are closed at their bottom or outer ends by conductive terminal plate members, for example [6 and i8, to which the receptacle contacts are physically secured and electrically connected by rivets 34. The terminal members may be secured against the bottom surface of the receptacle by bolts such as 26, passing through the bottom'of the receptacle and having their heads located in passageways 28, which passageways may be filled with wax (not shown) in conventional fashion. The number of receptacle contacts, pockets and terminals will depend on the circuit arrangement which the switch is to control. For illustration of one preferred form, Fig. 4 shows three line terminals l5, l8, l1 and four load terminals I8a, l8b, I80, l8d. If desired, the middle line terminal I 8 may be offset from the plane of the other line terminals. For this purpose the pocket or recess, for its associated receptacle contact, may be more deeply molded into the bottom surface of the receptacle body. A ledge 34 against which the terminal 38 may lie. may be formed in inwardly oflset position relative to the plane of the bottom of the receptacle body.

Preferably the top surface of the receptacle will be planar so as to lie against or adjacent to the under surface of the panel P.

To economize on molding material and to provide space for the portion of the switch unit which contains the indexing means (hereinafter described) the central portion Ilc of the receptacle and certain other portions 14a, Mb extending therefrom may be hollowed out more deeply than the remainder; with the result that the receptacle contacts 20 appear to be located beneath the surface of ledges H.

The switch unit S comprises a body 50 of generally cylindrical shape molded from insulating material. The body 50 is hollowed out from its upper surface to receive the fixed and movable switch operating parts.

For operating the switch, a disc shaped insulating handle or operating member 60 completely covers the open top of the insulating body 50. The operating member 80 has molded into it, so as to turn therewith, spindle 62. The spindle 62 has in its mid portion a square section 64 passing through a square aperture in a circular contact operating cam member 86 molded from insulation. This member seats and slides rotatably upon a platform 68 rising in the center of the floor of the body 50. On the under side of the cam 66 are concentric circular cam tracks 69 and 10 having cam surfaces on two or more different levels. These cam tracks are adapted to engage cam portions 12, I4 lanced upwardly out of a pair of parallel resilient leaf spring contact strips 18, 18 which extend tangentially across the switch body 50 on opposite sides of the spindle 64 (Figs. 1, 3, 5). These leaf spring contact members are secured at one end (the right end in Fig. 5 or the left end in Fig. 6) upon low ledges just above the floor, while their other ends bear contact buttons such as 160 which can engage and disengage fixed contact buttons such as 880 located on the underside of stationary contact members 80 and 82. Members 88 and 82 may be identical and located at opposite sides of the body 58 on ledges of that body at a level above the ledges on which the con-- tact springs 16, 18 are supported. Portions of said contact members 80 and 82 extend over the ends of the movable contact springs 16 and 18, and contact buttons are mounted on both top and bottom surfaces of said contact members.

An additional pair of movable contact members 96 and 98 are located above and parallel to the previously described movable contact springs 16 and 18. These upper contact members are actuated in a similar manner to the lower contact springs, that is by means of concentric cam tracks. These tracks are molded upon the underside of the operating disc or member 60. The springs 96 and 98 are riveted at one end (the right end in Figs. 5 and 6 and the left end in Fig. 1) to identical terminal members and 82 stamped from sheet metal and secured upon ledges at a level above contact members 80 and 82. The other ends of the contact springs 96 and 98 have contact buttons on both their upper and lower surfaces. The buttons on the lower surfaces are adapted to engage and disengage the contact buttons on the upper surfaces of the fixed contact members 80 and 82 respectively, while the contact buttons on the upper surfaces of the springs 98 and 98 are adapted to engage and disengage contact buttons e. g. 188a, on the lower surface at opposite ends of a common arcuate contact member I00. Member I 00 may be stamped from sheet metal and is secured upon a ledge between the movable contacts and at a level above the terminal members and 92.

Thus as the operating member 88 is rotated, the cam surfaces on its underside and the cam surfaces on the underside of the cam member 68 will rotate and cause flexing of the several contact springs, which in turn cause engagement or disengagement of the respective, fixed and movable contacts for the purpose of making and breaking various circuit connections. Those connections in themselves do not form any part of the present invention.

Conventional indexing means such as spring pressed balls may be associated with the switch spindle 64 to cause it to remain in its several positions.

The fixed contact members 80, 82 and I00, and the terminals 90 and 92 for the movable contact springs 96 and 98, and also the terminals for the contact springs 16 and 18 are secured to the body 50 at the various levels previously indicated by similar means which serve not only as the means for securing said parts of the body 50, but also as means for connecting said parts electrically with complementary receptacle contacts in the receptacle R. Said means comprise a cylindrical contact finger 2| such as a brass rod which extends from the bottom surface of the switch body 50 and has a narrow neck 23 extending upwardly through the bottom of the body 50 and through an aperture in the associated contact and terminal mem- .ber for example I00, and has the inner end of the neck peened over on to the contact or terminal member to hold the same in place and simultaneously to electrically connect therewith. All the plug contact fingers are substantially alike except for dimensional differences in length of the finger or its neck.

The panel aperture ill will ordinarily be circular and of such diameter as to permit the insertion of the body 50 which body will substantially fill the aperture l8. Regardless of shape of the body 50 it is desirable to completely cover the aperture in so as to prevent any possible access to the live parts within the receptacle or in back of the panel. For that purpose a circular or peripheral flange SM is provided on the switch body to overlie the edge of the aperture l0. Thus when the switch unit is plugged in, the aperture is completely covered by the switch unit; also, the switch parts themselves are covered by the insulated operating disc 89.

From the foregoing it will be apparent that by properly locating the several plug fingers so as to register with the several openings 24 in the pockets 22 within which the receptacle members 20 are located, it will be possible to insert the switch as an assembled unit into the receptacle, after or while the receptacle is mounted behind the panel P. Also the switch unit may be removed by simply pulling it away from the receptacle without disturbing the relationship of the receptacle and panel. When the switch is inserted, all live parts are completely protected against accidental contact; and when the switch is removed the receptacle contacts are nevertheless shielded and protected.

Many modifications within the scope of my invention will occur to those skilled in the art, therefore I do not limit my invention to the specific embodiment illustrated and described.

I claim:

1. An electric switch unit comprising an insulating body havinga cavity; switch contacts within said cavity, and an insulated operating member for said contacts covering said cavity; a. panel member having an aperture fitting said body; an insulating base structure mounted entirely behind said panel; connector contact members on said base structure, connector contact members on said switch body electrically connected with said switch contacts, said body connector members cooperating with said base connector members upon insertion of said switch body through said aperture, whereby live switch parts are shielded by said body and its covering operating member, and live base parts are shielded by said panel and interfitting engagement therewith of said body. 1

2. An electric switch unit comprising an insulating body having a cavity, switch contacts within said cavity, and an insulated operating member for said contacts covering said cavity; a panel member having an aperture receiving said body; an insulating base structure mounted entirely behind said panel; connector contact members on said base structure, connector contact members on said switch body electrically connected with said switch contacts, said body connector members cooperating with said base connector members upon insertion of said switch body through said aperture, and a flange on said body overlying the peripheral edges of said aperture, whereby the live parts of said switch and base are covered by said insulating parts and panel.

3. A plug-in switch apparatus as claimed in claim 1 characterized by the formation of said switch and panel structures to permit insertion of the switch structure as a complete unit into, and withdrawal from, said base structure while said panel and base structures remain assembled. 4. A plug-in switch apparatus as claimed in claim 2 characterized by the formation of said switch and panel structures to permit insertion of the switch structures as a complete unit into, and withdrawal from, said base structure while said panel and base structures remain assembled.

FREDERIC P. GATES.

REFERENCES CITED The following references are of record in the file of this patent: 

